Home > Articles > Home & Office Computing > Entertainment/Gaming/Gadgets

  • Print
  • + Share This
This chapter is from the book

This chapter is from the book

What Is Exif?

This chapter refers to your photo’s Exif information. What exactly is this? Simply put, Exchangeable Image File Format information is a file format that records associated information with the photo being shot.

Exif information is always displayed at the top of iPhoto’s Information Pane.

  1. Camera name: This is the name of the camera you took the selected photo with. In this case, it was a Canon PowerShot SD850 IS.
  2. White balance: The letters AWB signify that the photo was taken using the camera’s automatic white balance. White balancing is a technique that ensures what’s white in real life shows up as white when you take a picture of it.
  3. Metering mode: This appears as the crosshairs in a rectangle box in the Exif window. The metering mode tells you the way your camera determined the photo’s exposure.
  4. Lens information: This displays the length of the camera’s optical lens, its f-stop, whether it has image stabilization, and more. What is displayed depends on the camera. In this case, iPhoto shows the camera (a Canon PowerShot SD850 IS) had a 5.8–23.2mm lens, but if you were using a more advanced camera—such as the Canon Rebel DSLR kit lens—iPhoto would show more info (such as Canon EF-S 19–55mm f/3.5–5.6 IS).
  5. Resolution: This shows you the resolution of the photo in pixels. The selected photo is 3264 pixels wide by 2448 pixels high.
  6. File size: This shows the size of the photo. It’s 1.6MB in this case.
  7. File type: This shows the file type of the photo. It’s JPEG in this case. Other common formats are TIFF, RAW, and PNG.

  8. ISO: ISO is a measure of how sensitive the image sensor in the camera is to the amount of light present. The higher the ISO, the more sensitive the image sensor is, which increases the ability to take pictures in low-light situations or at faster shutter speeds in normal lighting. Many cameras allow multiple ISO settings, the trade-off being that higher ISOs have greater amounts of noise.
  9. Focal length: The focal length determines how much your camera can see. It’s the distance between the center of the lens and its focus. In this case, the focal length of the photo is 11.82mm. Also note that in the case of a zoom lens, such as this camera’s 5.8–23.2mm lens, the higher number means a higher amount of zoom.
  10. Exposure compensation: Basically, exposure compensation allows your camera to automatically brighten or darken images so you can get the best picture possible. A number followed by the letters EV designates exposure compensation. In this case, the photo’s exposure compensation was 0.
  11. Aperture: The aperture is the size of the opening in the camera lens while taking a photograph. This limits the amount of light entering the lens. It is designated by f/ followed by a number. The higher the number, the smaller the aperture. Higher numbers mean less light. The aperture in the example is f/4.

  12. Shutter speed: This is the length of time the camera’s shutter is open. Shutter speed is generally longer in night shots because the length of time the shutter is open must be longer in order to take in the appropriate amount of light. The shutter speed of the photo in the example is 1/640—that means the shutter was open for 1/640th of a second.
  13. Filename: Camera manufacturers use conventional standards when naming photos you have taken. These names often begin with DSC_ or IMG_; in the example, the name the camera assigned to the photograph is IMG_1746.JPG.
  14. Date and time: This is the date and time you took your photograph. This is the only Exif information iPhoto allows you to alter. You find out how to change this later in this chapter.

  • + Share This
  • 🔖 Save To Your Account